Within the context of modern digital phased array (DPA) radios, differential Radio Frequency (RF) front-ends provide much greater immunity to noise and distortion by suppressing second order harmonics. Recent advancements in differential RF front-ends offer high dynamic range, high linearity, and low noise in the transceiver chain. However, a major roadblock to fully differential systems is the presence of common-mode resonances. In this article, we present a novel wideband differential feed for dipole arrays that overcomes this bottleneck. Our dipole array is developed for the L-S band ( viz. 1.05 GHz to 3.2 GHz) with emphasis on dual-linear polarization and resonance-free scanning to low angles. The novelty of this article is the Balanced Wideband Impedance Transformer (BWIT) feed that mitigates common-mode currents across the entire band while scanning to low angles. Array simulations are verified with measurements of an $8\times 8$ prototype in a volume of 384mm $\times 384$ mm $\times 57$ mm. The array achieves resonance-free scanning across a 3:1 impedance bandwidth with VSWR < 3 for the cases of $\theta = 0^{\circ }$ (Broadside), 45° (D-plane), 60° (E-plane) and across a 2.37:1 impedance bandwidth with VSWR < 3 for the case of 45° (H-plane). Measured gain achieves near-theoretical values across the operating band.

中文翻译：

---

带有平衡宽带阻抗变压器（BWIT）的宽带偶极阵列

在现代数字相控阵（DPA）无线电的背景下，差分射频（RF）前端通过抑制二阶谐波提供了更大的抗噪声和失真能力。差分RF前端的最新进展在收发器链中提供了高动态范围，高线性度和低噪声。但是，全差动系统的主要障碍是共模谐振的存在。在本文中，我们提出了一种新型的偶极阵列宽带差分馈电，克服了这一瓶颈。我们的偶极阵列是针对LS波段开发的（ 即1.05 GHz至3.2 GHz），重点放在双线性极化和低共振无扫描。本文的新颖之处在于平衡宽带阻抗变压器（BWIT）信号源，该信号源可在扫描至低角度时减轻整个频带上的共模电流。阵列仿真通过测量 $ 8 /次8 $ 体积为384mm的原型 $ \次384 $ 毫米 $ \次57 $ 毫米 对于以下情况，该阵列可在VSWR <3的情况下在3：1阻抗带宽上实现无共振扫描。 $ \ theta = 0 ^ {\ circ} $ （宽边），45°（D平面），60°（E平面），并且在45°（H平面）情况下，VSWR <3时的阻抗带宽为2.37：1。测得的增益在整个工作频带内达到接近理论值。